Stop mechanism for knitting machines



May 2, 1950 H. c. GRANT STOP MECHANISM FOR KNITTING MACHINES Filed Sept. 3, 1948 HORACE. CGRANT ATTORNEYS Patented May 2, 1950 UNITED STATES TENT OFFIC STU? MECHANISM FOR KNITTING MACHINES Horace C. Grant, Atlanta, Ga., assignor to Egan Cotton Mills, Inc, Atlanta, Ga., a corporation of Georgia 2 Claims.

In Patent No. 1,816,416 to Willingham is described a knitting machine for forming a fabric consisting of successive transverse plies of roving by the use of front and rear needles between which the roving is laid. In that machine if the roving is not laid correctly, the thread guides feeding the thread to the needles will be impeded in their action, thus preventing the proper looping of the threads around the needles with the result that an imperfect fabric will be formed. This invention has for its object to provide a mechanism for stopping the machine if such interference with the movement of the thread guide takes place.

Referring to the accompanying drawings, in which corresponding parts are designated by corresponding marks of reference,

Figure l is a view representing my present invention, the parts being in a position assumed during a correct feeding of the roving.

Figure 2 is a similar view (fragmental) showing an improperly laid roving.

Figure 3 is a detail of the contact mechanism tending to stop the machine.

Figure 4 is a section on line X-d-X-4 of Figure 3.

Figure 5 is a diagrammatic view showing the control circuits.

As in the said Willingham patent the roving a is laid on top of a guide frame consisting of the front and rear walls 2 between which the fabric as knit passes down. The knitting is effected by front and rear needles 5 and B vertically reciprocating in alternation, around which the knitting thread is looped by the front and back oscillation of the thread guide carrier I'm having thread guide fingers l1 projecting downwardly therefrom and moving through the spaces between adjacent needles, the cycle being such that a ply of roving is laid on the guide frame while the thread guide is in its rear position and the rear needles are raised. The front needles are then raised and the thread guide carrier moves forwardly to loop the thread around such needles. The feeding of the roving is due, as in the Willingham patent, to a transversely reciprocating roving feeder.

As in the Willingham patent the thread guide frame hangs from and is fixed on a rocker shaft 20 having an arm 20a connected to the upper end of a pitman 201) by which the necessary oscillations may be given to the rocker shaft and to the thread guide frame. According to my present invention the pitman has mounted on its lower end a roller 25 normally held on the periphery of a cam 26 by a spring 30, the cam being mounted on the main drive shaft 8, a yoke 200 being formed in the pitman to encircle the drive shaft and guide its lower end. When the small part 26a of the cam comes under the roller 25 the latter may drop with the resultant movement of the thread guide fingers to the front and between the then raised front needles. This is proper operation.

However, if the roving is not laid flat on the preceding ply, but for any reason rides against the front needles 5 as is shown in Figure 2, the forward swing of the thread guide frame will be prevented and imperfect knitting will result.

To stop the machine under such circumstances I provide a resilient contact arm 35 projecting from the lower part of the pitman and adapted to contact with an ear 35a, on the arm 3% fast on the cam and so positioned that if the roller is not in the reduced portion of the cam when the arm 35b moves by it, an electrical circuit 40 will be closed actuating the relay lllla in such circuit and thus breaking the circuit 4| of the driving motor Ma of the machine. If, however, the roller is following the reduced portion of the cam the ear 3512 on the arm will sweep past the plate above the latter without closing the control circuit.

Having thus described my invention what I claim is:

1. In a stop mechanism for a knitting machine in which plies of roving are laid between front and rear needles, the combination of an oscillating thread guide swinging from front to rear and having thread guide fingers passing between adjacent needles in such movement, means for resiliently swinging such fingers towards the front of the machine and means for stopping the machine when such movement of the fingers is prevented by an imperfectly laid ply.

2. In a stop mechanism for a knitting machine in which plies of roving are laid between front and rear needles, the combination of an oscillating thread guide swinging from front to rear and having thread guide fingers passing between ad- J'acent needles in such movement, a cam actuating the said thread guide in one direction, :a pitman having its lower end running on the cam, cooperating contacts on the pitman and on the cam when the contact on the cam passes the pitman with the roller off the cam and a control circuit for the machine controlled by said contacts.

HORACE C. GRANT.

Name Date Willingham July 28 1931 Number 

